The present invention relates to a novel naphthol derivative, which can be used as a coupler component of an azo compound, which is useful for dyes, pigments, photosensitive materials and the like. The present invention also relates to an azo compound and a metal complex which are synthesized with the naphthol derivative.
Naphthol derivatives are the most economical compounds among the condensed aromatic compounds, which can form conjugated polyene systems and have adsorption in the electron band, and are easily used as raw materials for synthesis of chemical materials. Therefore, it has hitherto been used for preparing various compounds, particularly for dyes, pigments, photosensitive materials and the like.
Some naphthol derivatives are known including 3- or 6- substituted 2-hydroxynaphthalene such as 2hydroxy-3phenylaminocarbonyl naphthalene and 2hydroxy-6-phenylaminocarbonyl naphthalene and those having further substituents, such as alkyl and alkoxy groups, on the phenyl group.
However, only 2-hydroxy-3,6-dihydroxycarbonyl naphthalene and derivatives thereof having amide or ester bonding, which are disclosed in WO98/16513, have been known as the naphthalene derivatives having substituents at both of 3- and 6-positions of 2-hydroxynaphthalene.
An object of the present invention is to provide a novel naphthol derivative, which is useful as a raw material for synthesizing chemical materials. Another object of the present invention is to provide monoazo, bisazo and trisazo compounds as well as metal complexes prepared with the novel naphthol derivative of the present invention.
Accordingly, the present invention provides a naphthol derivative represented by general formula (1): 
wherein each Y1 and Y2 is independently selected from the group consisting of carboxyl, esterified carboxyl, amidated carboxyl and a group represented by general formula (2) 
xe2x80x83wherein
X1 is xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94 or xe2x80x94NHxe2x80x94,
Z is an optionally substituted aromatic or heterocyclic group having conjugated double bonds,
provided that at least one of Y1 and Y2 is a group represented by formula (2);
Q is selected from the group consisting of optionally branched alkyl and alkoxy groups each having 1-6 carbon atoms, halogen atom, nitro and nitroso groups,
m is an integer of 0-3;
R is selected from the group consisting of hydrogen atom, alkaline metal, optionally branched and optionally substituted alkyl and acyl groups each having 1-20 carbon atoms and phenyl alkyl group;
and a salt thereof.
In another embodiment of the present invention, novel monoazo, bisazo and trisazo compounds, which may be prepared with the naphthol derivative or the salt thereof of the present invention are also provided.
In a further embodiment of the present invention, a novel metal complex, which may be prepared with the naphthol derivative or the salt thereof of the present invention is also provided.